I'm a half-size and I ordered based on the reviews and bought a half-size too big. BIG MISTAKE!!! The shoes fit perfectly for a day and then stretched out! BUT my mom (who's a whole size larger than me) tried them on and LOVED them!! So she got to keep them and I had to order another pair for myself! They're super comfy!! It really is like having a comfy sweatshirt on your feet! Not too warm and not to cold -- just right!